The relationship between overwork and health-related issues among systems engineers (SEs) and programmers (PGs) has been recently gaining attention, as the working environment continues to change rapidly due to the information technology revolution. This study elucidated the actual conditions and characteristics of SEs and PGs who were approved for industrial accident compensation insurance for overwork-related disorders and shed light on how to prevent Karoshi and other Overwork-related Health Disorders. We analyzed 51 cases of cerebrovascular/cardiovascular diseases (CCVD) and 85 cases of mental disorders due to overwork between 2010 and 2015 in the information and communications technology industry. Among the participants studied, more than 90% of the CCVD cases involved people under the age of 50 years, and 90% of the death cases were caused due to heart diseases; in addition, it was observed that the onset of a disorder occurred after a period of three months wherein the number of overtime hours exceeded 80 hours. Among cases of mental disorders, the suicide rate exceeded 30%, about 75% were under the age of 50 years, and more than 75% experienced episodes of depression. In the events with psychological load, the ratio of long working hours was high. Particularly suicide cases that included interpersonal relationships and changes in roles and positions were higher than survival cases. From these findings, implementing appropriate work time management, improving work efficiency, and reducing workload due to long working hours for young and middle-aged employees might contribute to the prevention of overwork-related disorders.

We simulated sweat as artificial biological solution containing electrolytes and organic chemicals, and attempted to develop a method of dermal exposure assessment of metals compounds by analyzing the metal concentration in artificial biological solution. Manganese oxides were selected as test materials, and artificial sweat solution containing 18 different electrolytes and organic chemicals was used as matrix sample. There was little interference, such as spectral interference, between the chemicals used in the artificial sweat and manganese ion, and ICP-AES was able to determine the manganese ion in the artificial sweat without dilution. On the other hand, the influence of chloride from sodium chloride was observed in the ICP-MS analysis, ICP-MS required more than 5-fold dilution so that sodium chloride in artificial sweat was less than 300 μg/L. The results of this study are considered to provide important information for the evaluation of dermal exposure of metal compounds.

The accidents on fall-down of exterior walls have occurred in demolition site of building. When the exterior walls are demolish, the lower part of the wall and column are cut. After that, the wall and column are pulled down.

This method is called to fall-down method. When the wall and column are cut too deeply while cutting work, the wall and column collapses and can crush the worker. In this study, the test reproduce the fall-down method was carried out for prevent collapse of the exterior wall. In the test, the column as the fundamental member in the exterior wall was targeted. From the result, the good cutting pattern for the lower column is the concrete on the falling side and the main reinforcement on opposite to falling side were cut, and the main reinforcement on falling side was left in place. And, analysis method was examined for predict of the strength of fall-down of column. The validity of the analysis method was examined by comparing the analysis results and the test results.

The Ministry of Health, Labour, and Welfare recommends prevention of occupational accidents due to awkward movement in the healthcare service field. This study aimed to determine risk factors of occupational accidents from actual case reports. A total of 1,041 case reports of occupational accidents due to awkward movement in the healthcare service were investigated using the text mining analysis. The number of occurrences for each word was counted, and the co-occurrence network for each word was obtained based on Jaccard coefficients. Results showed that “lower back,” “bed,” “care,” “pain,” “transfer,” “patient,” and “wheelchair” co-occurred in many accident reports. Results suggested that occupational accidents with lower back pain frequently occurred while transferring patients from bed to wheelchair. A previous study in 2008 also reported these risk factors. However, these risk factors remain to be solved. Therefore, urgent and more effective countermeasures are necessary to prevent lower back pain because of transfer.

“White fingers” is a well-known symptom of Hand-Arm-Vibration-Syndrome (HAVS) in Japan. Although the number of HAVS cases is declining due to limited working time and the invention of HAV tools, it is estimated that there is still over a million workers who use hand-arm vibrating tools in the manufacturing industry. Among these workers, only 63,000 have undergone specific health checkup for vibration. Because of its convenience and simplicity, laser speckle flowgraphy (LSFG) may be an efficient device for detecting early-stage HAVS in peripheral blood flow. This study aimed to evaluate the relationship between peripheral blood flow changes and cumulative vibration exposure and to elucidate the efficiency of the cold water immersion test, using LSFG, in screening vibration damage. In this study, we could not determine a relationship between peripheral blood flow and cumulative vibration exposure. However, the objectivity and reproducibility of the LSFG could be used to the occupational health check-up of vibration diseases. Further investigation is required for the actual use of this examination using the LSFG.

Professional wine tasters have been reported to be at risk of dental erosion. However, there are few studies investigating workers who frequently take acid drinks in Japan. The purpose of this study was investigating the factors associated with dental erosion among wine manufacturing workers. We conducted an oral examination and a selfreported questionnaire survey for workers of 6 wine manufactures in Japan in 2019. Ninty five workers (male: 71 workers, female: 24 workers) were analyzed. Dental erosion was observed in 31 workers (32.6%). As the result of multiple logistic regression analysis, frequent job-related drinking or eating was significantly associated with dental erosion [odds ratio (OR): 5.64, 95% confidence interval (CI): 1.77-17.91]. Therefore, it might be effective for the workers of wine manufactures to encourage regular dental visits for preventing dental erosion.